Control system



March 28, 1944.

CONTROL SYSTEM 2 Sheets-Sheet 1 Filed Oct. 21, 1942 mm um umzwmumm QU T 0Q UHHIHJ I mm mm Tllll.

mm m6 Gltorncu March 28, 1944. B. B. SMITH ET AL 2,345,362

' CONTROL SYSTEM Filed Oct. 21, 1942 2 Sheets-Sheet 2 om M .N MN mm m hm R wmmmm mm m H- mm m mm M mm mm E m Hr Q wv NV O? dttorn'cu Patented Mar. 28, 1944 UNITED STATES PATENT: oFFios CONTROL SYSTEM Burwell B. Smith and Earl E. Hilker, York, Pa., assignors to S. Morgan Smith Company, York, Pa., a corporation of Pennsylvania Application October 21, 1942, Serial No. 462,806 I 4 Claims. (01. 137-78) f This invention relates to control systems, and more particularly to control systems for pipe lines of the type having a check valve on the discharge side of a pump.

In our application for Letters Patent which was filed in the United States Patent Oflice October 14, 1942, Serial No. 4615962, for Control system, there is shown and. described a control system designed to protect the discharge line from a pumping station against excessive pressure rise caused by a rapid shut down of the pumping unit and a fast closure of the check valve.

In the control system of the above referred to pending patent application, the check valve is adapted to be operated automatically according to variations in the pressure of fluid in the pipe line in such a manner that under normal conditions the valve operating mechanism is controlled so as to effect closing of the check valve at a relatively slow rate of speed, While during emergency or abnormal conditions the average time to close the check valve is many times faster than the normal closing rate.

Associated with the check valve of the above referred to pending patent application, is a relief valve which is connected by a vent pip with the main pipe and which has a valve element normally closed. Means are provided for operating the valve element of the relief valve, such means including a dash pot device normally movable at a slow rate of speed when the check valve is operated under predetermined normal conditions so as to prevent operation of the relief valve to open communication to vent fluid from the main pipe line, the dash pot device being adapted, when moved rapidly, to effect opening of the relief valve, so that when the check valve is moved towards closed position at a rapid rate of speed the relief valve will be opened and thereby prevent excessive pressure rises in the main pipe line resulting from the rapid closing of the check valve.

In the above referred to pending patent application the mechanism for controlling the operation of the relief valve is connected to the operating shaft of the plug of the check valve by a series of links and levers. In other words, the relief valve mechanism is directly connected to the operating mechanism of the check valve by mechanical means. The advantage of such mechanical hook up of the relief valve with the check valve is that, under some conditions of installation, it is necessary to arrange the relief valve in proximity to the check valve, and when tage to directly: connect the relief valve mechanism to the check valve operating mechanism.

On the other .hand; under some conditions of installation, it is not possible to locate the relief valve close to the check valve. When SllCh'BOllditions arise,'it' may be necessary to connect'the relief valve to the main pipe line at apoint remote to the check valve,-' and the present invention relates to such a controlsystem in which the relief valve is disposed at a considerable distance from the check valve. -I

An object of the present invention is to provide an improved control system for a pipeline of the type having acheck valve on the discharge side of a pump, in which a {relief valve is connected to the pipeline at a point downstream with respect to. the check valve, and in which there are improved electrically controlled means operatively connecting the 'relief valve with the check valve so that when the check valve is operated under certain conditions the relief valve will not be operated to discharge fluid from-the pipe line, and when the check valve-is operated under other conditions tocut off the flow of fluid in the pipe line,- the relief valve Will-be operated to discharge fluid from the pipe line on the downstream side of the check valve.

Another object of the invention is to provide an; improved combined electrical and mechanical control system of the abovetype which is so' arranged that the relief valve can be disposed at a point remote from the check valve. a With the foregoing and other objects and advantages in view, the invention consists in the 7 preferred constructionand arrangement of the several parts which will be hereinafter fully described and claimed.- In the accompanying drawings Fig. l is a diagrammatic-view of. a control system embodying the present invention;

Fig. 2 is an enlarged, vie w of a portion of the structure shownin--Fig. 1,- parts being illustrated in section; and Fig: 3 is an enlarged vertical section-of the relief valve shown in Fig. 1.- -"Referring to the drawings; and especially-to Fig. 1, at a convenient point on the pressure side of a pump (not shown), theipipe line has installed therein an automatically operable check valve I l.

The check valve Hv may be of the type shown in the following United States Letters Patent, namely, #2219359; granted October 29,1940, for Control system, invented by Laurence E. Goit and such a. close arrangement is made, it is of advan- Eueene' risbane; #23 3 7, granted v her 5, 1940, for Control system, invented by Laurence E. Goit and Eugene C. Brisbane; and #2,232,901, granted February 25, 1941, for a Valve, invented by Eugene C. Brisbane.

Patents #2,219,359 and #2,220,327 each relate to a control system for the power operated mechanism of a valve installed in a pipe line on the pressure Side of a motor driven pump, in which electromagnetically operated means are associated with the circuit supplying current to the pump motor so as to be responsive to line connections for said motor to control the operation of the valve mechanism.

In Patent #2,232,901 the check valve, which is located in the pipe line on the pressure side of a pump, has operating mechanismwhich is controlled in such a manner that, under normal conditions, the valve operating mechanism is controlled so as to effect closing of the valve plug 'in approximately forty seconds, while during closing operation. of the valve plug under emergency or abnormal conditions, the average time to close the valve plug is approximately five secends, or eight times faster than the normal closing rate.

When a valve is operated quickly to shut ofi communication through a pipe line, such. as is described in Patent a l-2,232,901, an excessive pressure rise occurs in the pipe line on the downstream side of the valve. Since this excessive rise influid pressure is detrimental and often causes fracture or breaks in the pipe line, it is of.- advantage to provide some means for preventing the occurrence of these excessive increases in the ressure oi the fluid.

According to the present invention, at some convenient point in the pipe line l2 on the downstream side of the check valve H,- a vent pipe I3 is connected to the pipe 12.

A relief valve I4 is" connected to the outer end of the vent pipe [3; V

The valve H may be of the type referred to in the above mentioned patents, and has a valve plug or gate I 5 which is formed with a waterway l6 adapted to register with the bore of the pipe l2 when the plug is in the open position shown.

The plug or gate I5 is adapted to be rotated by suitable mechanism, as described in either one of the three patents above referred to, which mechanism is not shown or described herein, since it is well known in the art. However, as a part of the valve operating mechanism, the plug [5 has a shaft H which extends beyond the valve casing a suitable distance, as shown in Patents $2,219,359 and #2220327.

The relief valve I4 comprises an elbow type of valve having a, casing 2| formed with a chamber 22, which is connected by a passage 23 to the vent pipe t3 leading from the main pipe I2, so that said chamber 22' is always in communication with saidmain pipe, and fluid under pressure in the main pipe I2 is always present in the valve chamber 22.

A piston valve 21 is mounted in a bore 28 formed in the body of the relief-valve I4.

The piston'valve 21 comprises a main body portion, which at one end is formed with a tapered portion 29 adapted to engage a seat 30 formed in th casing 2|.

The end of the piston valve 21 opposite to the tapered portion 29 is formed with a head or piston 31 Which is mounted in a cylinder 32.

The piston valve- 21 is adapted to control communicat-ion from chamber 22 to a passage 33 adapted to be connected to a free discharge or sewer. If so desired, the free discharge to which passage 33 is adapted to be connected may be the suction well of the pump (not shown), as is well known in th art.

The valve seat 30 is preferably formed at the upper end of passage 33, so that when the piston valve 21 is seated communication is shut off from chamber 22 to the free discharge.

The chamber 35 on the lower side or the piston Si is adapted to be supplied with pipe line fluid through a pipe. connection 36.

Chamber 3'! on the upper side of the piston 3i is also supplied with pipe line fluid from pipe 36, through a branch pipe 38 having a valve 39 installed therein.

Preferably valve 39 is of the needle or other suitable form of valve adapted to provide an adjustable restricted. orifice for regulating the amount of fluid admitted to the chamber 31 on the upper side of the piston 3|.

As shown in Fig. 1, the connection or pipe 36 may be connected to the pipe line l2, preferably on the downstream side of the check valve H.

Associated with the relief valve I4, is an. exhaust valve device 4l,,comprising a valve body having an upper or pressure chamber 42 con-- nected to the'piston chamber 31 of the relief valve M by a pipe 43, and a lower or exhaust chamber 44 connected to a free discharge or sewer by a pipe 45.

The chambers 42 and 44 are separated by a wall having a passage formed therein defining a valve seat 45 for a valve 41 disposed in chamber Extending upwardly from the valve 4'! is a stem 48 which is fixed to the plunger of a solenoid or relay device 49.

The coil of the solenoid or relay 49 is con nected by wires 50 and 5| to two contact terminals 52 and 53, respectively, of a suitable switch device 54.

The switch 54 has a pair of blades or switch arms and 5B which are respectively connected by wires or conductors 51 and 58, to a suitable source of electric energy, such as a storage bat tery 59. g

The switch blades 55 and 55 are connected by an arm which is adapted to move the'end portions of said blades into and out of contact with the terminals 52 and 53, respectively. When the blades engage the terminals 52 and 53', the solenoid, being energized, will operate the valve 41 so as to connect chamber 42 with chamber 44 thereby exhausting fluid under pressure from piston chamber 31 to the free discharge.

Normally, the switch blades 55 and 56 are maintained disengaged from the contact terminals 52 and 53, by suitable means, such as spring 6|.

The arm 6!! depends from the switch 54 into the path of a lever 63 pivotally connected by a pin 64, to a bracket so that said lever can be rocked or swung to move the arm 60 whereby the blades 55 and 55 are moved into engagement with the contact terminals 52' and*53, respectively.

The other end of lever 53 is pivotally connected, as at B6, to a stem projecting from one end of a flexible connector device 61'.

The flexible connector device 61 constitutes a collaspsible or telescoping link between an end of lever 63 and the end of another lever 68;

The flexible connector device comprises a cylinder having one end portion pivotally connected by pin 65 to the end of lever 63. Mounted withinthe cylinder of the flexible connector device 61 is the headed end '69 of a rod or link Disposed within the cylindrical body of the flexible connector device 61, is a coil spring 12, one end of which bears against an abutment provided by end wall 13 of the cylinder and the other end of which bears the rod 10.

Normally the spring 12 is extended and retains the head 69 against the abutment provided by end wall 14 of the cylinder 61.

During operation of the device, after lever 68 has actuated lever 63 an amount to operate the arm 60 of the switch 54, should the lever 68 continue to move after the arm 60 has been ac tuated its maximum amount, the rod or link 10 will compress spring 12 and in doing so the operating forces of'lever'68 will not be transmitted by lever 83 to arm 69, since the driving connection between lever 83 and lever 68 will telescope, as will be understood.

Fixed to the valve plug shaft I! is a crank 16, to the outer end of which is pivotally connected by a pin 11, the upper end of the piston rod 18 of a dash pot device 19.

The dash pot device I9 comprises a casing or housing 80 which is secured to cover plate 8| of the checkvalve I I, said casing 88 constituting a guide for the dash pot cylinder 82 which is slidably mounted therein in the manner best showninFig. 2.

An elongated slot 83 is formed in the wall of the housing 80, as shown in Fig. 1.

- Lever 68 is pivotally mounted intermediate its length by a pin 84 carried by a bracket 85.

The end of the lever 68 opposite to the end having the pivot pin H, is pivotally connected to the dash pot cylinder 82, by a pin 8'6, the construction and arrangement of the parts being such that rectilinear movementsof the dash pot cylinder 82 effect swinging movements of the lever 68 about the fulcrum provided by the pivot 84, and-these swinging movements of the lever 88 actuate the switch operating lever 63 through the flexible connector 81.

The dash pot cylinder 82 is freely movable rectilinearly within the guide 80, the upper rectilinear movement of said cylinder being limited by the stop provided by a shoulder 81 formed at the upper end of the guide 88, against which shoulder the upper end of the-dash pot cylinder 82 abuts when the device is inactive, as shown in Fig. '2. Thus, when the valve 41 is seated and the switch device 54 open, the spring 12 forces-the head 69 into contact with abutment 14, the rod or link 10 and lever 68 will dispose the dash pot cylinder 82 in its guide 80 so that the upper end said cylinder 82 engages shoulder 81.

Mounted within the cylinder 82 is a piston 88 which is fastened to-the lower end of the piston rod 18.

The cylinder 82 contains a suitable quantity of fluid for controlling the movement of the piston 88 therein in well known manner.

The piston 88 is formed with a restricted orifice 89 through which the fluid within the cylinder 82 is by-passed at a predetermined rate. Also formed in the piston 8-8 is a second orifice 98, the flow of fluidthrough which is controlled by a spring actuated valve 9| mounted in the piston in such a manner that, during movement or the piston in one direction within the cylinagainst the head 89 of der, the valve remains seated, and during movement of the piston within the cylinder in the opposite direction, the valve 9| is unseated so that fluid can flow through the second orifice 90. Orifice 90 has a larger area than the area of restricted orifice 89, so that when the valve 9| is unseated a considerable amount of fluid will by-pass the dash pot piston.-

Mounted in chamber 92 on'the upper side of piston 88 and encircling the piston rod 18 is a coil spring 93.

- The construction of piston 88 and the arrangement of the valve 9| is such that, when the piston is moved downwardly, the valve 9| is retained in position to cut off communication through the orifice 9B, and since the fluid can only pass through the small opening or orifice 89, the downward movement of the piston is retarded.

Since the orifice 89 restricts the flow of fluid in the dash pot from one side of the piston to the other side of said piston, when said piston is actuated rapidly the fluid cannot flow through the orifice 89 in a suiflcient volume or quantity to displace the piston, and, consequently the pis ton is held by the fluid in its relative position in the cylinder 82. Thus, since the piston 88 is immovable with respect to the cylinder 82, the cylinder 82 is also moved in the same direction with the piston.

On the other hand, when the piston 88 i actuated at a predetermined slow rate of speed, the fluid within the dash pot cylinder 82 can pass through the orifice 89, and in doing so the pis ton 88 will move within the cylinder without affecting the position of the cylinder 82 in its guide 88.

Thus, summarizing the operation of the dash pot device 19, it will be noted that When forces are applied to move the piston 88'with rapidity the cylinder 82 will also be moved, and when the actuating forces applied to the piston 88 move said piston at a predetermined slow rate, piston 88 will move within the dash pot cylinder 82 without affecting the relative position of said cylinder.

In operation, when the check valve plug I5 is turned at a predetermined normal or slow rate of speed in the direction of the arrows, Figs. '1 and 2, from open to closed position, which rotative movement of said plug is through an angle of approximately 90 degrees, the crank or arm 16 on the end of the plug shaft 11 will also be turned through a corresponding angle, and during such movement, the piston 88 of the dash pot will be forced by its rod 18 downwardly within the cylinder 82, and this downward piston movement within cylinder 82 is slow so that the fluid in the chamber 94 on the lower side of said piston will pass through the restricted orifice 89 i in the piston to the chamber 92 on the upper side of said piston in well known manner, and the cylinder 82 will not be displaced from its position in the guide against shoulder 81. Consequently, lever 68 will not be operated and the piston valve 21 will remain seated against seat 30.

Thus, any time the valve plug I5 is moved from open towards closed position at its normal or slow turning rate of speed, the relief valve M will remain inactive.

On the other hand, when the valve plug I5 is actuated and turned from open position shown in Figs. 1 and 2, towards closed position at a fast rate of speed, as has heretofore been referred to, the dash pot piston 88 is actuated in such a manner that, due to the resistance of the fluid within the cylinder 82, the piston 88 forces the cylinder 82 downwardly within its guide 8l'l.

Thus, when the cylinder 82 is moved downwardly in its guide 80, through the operation of the dash pot piston 88 in the above referred to rapid manner, lever 68 is swung by cylinder 82 about the fulcrum provided by pivot 84, and this action is transmitted to lever 63, by the flexible connector 61, so that switch arm 60' is actuated and connects the blades 55 and 56 with contacts 52 and 53, respectively.

The instant switch 54 is closed and the solenoid 49 energized, thereby causing the exhaust valve 41 to move away from its seat 46, and connecting chamber 42 with chamber 44, fluid under pressure in piston chamber 31 is vented to the sewer, through pipe 43, chambers 42 and 44, and pipe 45.

The pressure of the fluid supplied to piston chamber 35 from pipe 35, acting on the bottom of piston 3|, causes the piston valve 21 to move rapidly upwardly away from the seat 30, thereby connecting chamber 22 with the free discharge provided by passage 33. The upward movement of the piston valve 21 away from seat 30 results in a quick discharge of fluid under pressure from the pipe 12, through vent pipe I3, passage 23, chamber 22, and passage 33, so that the pressure of the fluid in the pipe I2 is quickly reduced.

When the piston valve 2! has completed its upward movement in the manner above described, fluid within dash pot cylinder 82 is gradually by-passed through the orifice 89 in piston 88 by the force of spring 93 tending to extend the distance between the end 95 of the dash pot cylinder 82 and piston 88. Thus, the cylinder 82 is moved within the guide 80 and with respect to the piston 88 until the end 95 of said cylinder abuts shoulder 81. In this position of the cylinder 82, lever 68 is restored to its original position, and the spring Bl disconnects the switch blades 55 and 56 from the contacts 52 and 53, respectively, thereby opening the circuit through which solenoid 49 is energized. With the solenoid thus deenergized, valve 41 closes and pressure of fluid in piston chamber 31 builds up at a rate determined by the setting of valve 39 in pipe 38. In actual practice the rate at which the fluid is supplied to piston chamber 31 is relatively slow so that the piston valve will be moved down towards the seat 30 very slowly, thereby gradually closing the communication from the pipe 12 to the free discharge provided by passage 33.

It will be understood that the details and construction hereinbefore described are illustrative only and that the invention as described and claimed is in no way limited thereby.

Having thus described our invention, What we claim is:

1. In a control system of the type described, the combination with a main pipe having a check valve therein for automatically controlling the flow of fluid therethrough, said check 'check valve gate is in open position and being arranged to retain the discharge port closed when the check valve gate is operated at a predetermined rate, an operating piston attached to said relief valve, said piston having differential areas so that the relief valve is normally held closed by pressure acting on its larger area; an exhaust valve device having a chamber in communication with the chamber in which the pressure acts on the larger area of the piston, said exhaust valve device having a solenoid operated valve arranged to be operated "when: the solenoid is energized for establishing communication from said exhaust valve chamber to a free discharge whereby operating fluid in said pistonchamber of large area i discharged through the free discharge of said exhaust valve so as to relieve the pressure acting on said larger area of the piston to thereby effect operation of said relief valve to establish communication from the main pipe through said discharge port so as to exhaust fluid under pressure in said main pipe, an electric switch device for controlling the sup--' ply of electric current to energize said solenoid and means operatively connecting said electric switch device with said check valve gatefor effecting operation of said switch device, said means being arranged ,to operate said switch de-' vice to energizesaid solenoid only on closing of said check valve gate at a rate greater than a predetermined amount, said means being so constructed and arranged that it effects opening of said switch a predetermined time after closing of said check valve.

2. In a control system of the type described, the combination with a main pipe having a check valve therein for automatically controlling the flow of fluid therethrough, said check valve having a gate, of a relief valve connected to the -main pipe and having a discharge port and a valve for controlling communication through said discharge port, said relief valve normally closing the discharge "port when the check valve gate is in open position and being arranged to retain the discharge port closed when the check valve gate is operated at a predetermined rate, an operating piston attached to said relief valve, said piston having differential areas so that the relief valve is normally held closed by pressure acting on its larger area, an exhaust valve device having a chamber in communica: tion with the chamber in which the pressure acts on the larger area of the piston, said exhaust valve device having a solenoid operated valve arranged to be operated when the solenoid is energized for establishing communication from said exhaust valve chamber to a free discharge whereby operating fluid in said piston chamber of larger area is discharged through the free discharge of said exhaust valve so as to relieve the pressure acting on said larger area of the piston to thereby eflect operation of said relief valve to establish communication from the main pipe through said discharge port so as to exhaust fluid under pressure in said main pipe, an electric switch device for controlling the supply of electric current. to said solenoid, said switch device being normally open and being arranged to be closed on closing of said check valve gate at a rate greater than a predetermined amount and being arranged to be opened at the completion of the closing movement of said check valve gate, a dash pot device for controlling the operation of said electric switch device, said dash pot device having a fixed guide, a dash pot cylinder mounted for rectilinear movements in said guide, a piston mounted within said dash pot cylinder, means for controlling the operation of the piston within said dash'pot cylinder whereby said cylinder is moved by said piston and whereby said piston is moved relatively with respect to said cylinder, a lever connected to said dash pot cylinder and actuated thereby, means operatively connecting said lever with said switch device, and means operatively connecting said dash pot piston to said check valve gate, said dash pot device being arranged to operate said switch device only on closing of said check valve gate at a rate greater than the predetermined amount said dash pot device being so constructed and arranged that it efiects opening of said switch a predetermined time after closing of said check valve.

3. In a control system of the type described, the combination with a main pipe having a check valve therein for automatically controlling the flow of fluid therethrough, said check valve having a gate, of a relief valve connected to the main pipe and having a discharge port and a valve for controlling communication through said discharge port, said relief valve normally closing the discharge port when the check valve gate is in open position and being arranged to retain the discharge port closed when the check valve gate is operated at a predetermined rate, an operating piston attached to said relief valve, said piston having differential areas so that the relief valve is normally held closed by pressure acting on its larger area, an exhaust valve device having a chamber in communication with the chamber in which the pressure acts on the larger area of the piston, said exhaust valve device having a solenoid operated valve arranged to be operated when the solenoid is energized for establishing communication from said exhaust valve chamber to a free discharge whereby operating fluid in said piston chamber of larger area is discharged through the free discharge of said exhaust valve so as to relieve the pressure acting on said larger area of the piston to thereby effect operation of said relief valve to establish communication from the main pipe through said discharge port so as to exhaust fluid under pressure in said main pipe, an electric switch device for controlling the supply of electric current to said solenoid, said switch device being normally open and being arranged to be closed on closing of said check valve gate at a rate greater than a predetermined amount and being arranged to be opened at the completion of the closing movement of said check valve gate, an arm for actuating said switch device, leverage mechanism for operating said switch arm, a dash pot device for operating said leverage mechanism, said dash pot device being normally inoperative on closing of said check valve gate at a predetermined rate and being operative to effect actuation of said leverage mechanism only on closing of said check valve gate at a rate greater than a predetermined amount, and means operatively connecting said dash pot de-- vice with said check valve gate said dash pot device being so constructed and arranged that it efiects opening of said switch a predetermined time after closing of said check valve.

4. In a control system of the type described, the combination with a main pipe having a check valve therein for automatically contrch ling the flow of fluid therethrough, said check valve having a gate, of a relief valve connected to the main pipe and having a discharge port and a valve for controlling communication through said discharge port, said relief valve normally closing the discharge port when the check valve gate is in open position and being arranged to retain the discharge port closed when the check valve gate is operated at a predetermined rate, an operating piston attached to said relief valve, said piston having differ ential areas so that the relief valv is normally held closed by pressure acting on its larger area, an exhaust valve device having a chamber in communication with the chamber in which the pressure acts on the larger area of the piston, said exhaust valve device having a valve arranged to be operated by a solenoid when the solenoid is energized to establish communication from said exhaust valve chamber to a free discharge whereby operating fluid in said piston chamber of larger area is discharged through the free discharge of said exhaust valve so as to relieve the pressure acting on said larger area of the piston to thereby effect operation of said relief valve to establish communication from the main pipe through said discharge port so as to exhaust fluid under pressure in said main pipe, a dash pot device having a fixed guide, a dash pot cylinder rectllinearly movable in said guide, a piston arranged within said dash pot cylinder and connected to said check valve gate, said dash pot piston normally being movable within said dash pot cylinder by operation of said check valve gate at a predetermined rate towards closed position without imparting a rectilinear movement of said dash pot cylinder within its guide, said dash pot piston being adapted when said check valve gate moves toward closed position at a rate greater than a predetermined amount, to impart a rectilinear movement to said dash pot cylinder, a switch device for controlling the supply of electric current to said solenoid, said switch device having a depending operating arm, a lever connected to said dash pot cylinder and actuated thereby, and means operatively connecting said lever with said switch device and including a member operated by said lever for engaging the switch arm to thereby close the electric circuit to said solenoid operated exhaust valve, whereby said exhaust valve device is normally inoperative on closing of said check valve gate at a predetermined rate and is operated to exhaust fluid under pressure from said piston chamber of larger area only on closing of said check valve gate at a rate greater than a predetermined amount said dash pot device being so constructed and arranged that it ellects opening of said switch a predetermined time after closing of said check valve.

BURWELL B. SMITH. EARL E. HILKER. 

